1. Field of the Invention
The present invention relates to a light source apparatus channeling light from a light source into an optical fiber.
2. Description of Related Art
In recent years, an LED light source apparatus has been used which takes an LED (light-emitting diode) as a light source and channels light from the LED into an optical fiber. In the LED light source apparatus currently in widespread use, light emitted from a light-emitting surface of the LED is collected by a lens and received on a light-receiving surface of the optical fiber. In order to improve optical connection efficiency, the light-emitting surface of the LED and the light-receiving surface of the optical fiber are positioned facing each other with a slight gap therebetween (see Japanese Patent Laid-open Publication No. H10-300987, paragraphs [0002], [0003], and [0063]).
Japanese Patent Laid-open Publication No. H10-300987 discloses the necessity of mutual positioning accuracy for both the LED and the optical fiber. When meeting this requirement, a light source apparatus can be used that includes an optical fiber fixating structure capable of mutually adjusting the positions in order to fixate the optical fiber with respect to the LED. Examples include an adjustment mechanism that adjusts a distance of the light-receiving surface of the optical fiber with respect to the light-emitting surface of the LED using a mechanism for displacement of the optical fiber in an axis direction, and that also matches a center position of the optical fiber with a specific region of the LED using mechanisms for displacement in each axis direction along the light-emitting surface of the LED (Japanese Patent Laid-open Publication Nos. S52-102746 and 2005-345984). A further example, although not a light source apparatus, is of a coupler connecting optical fibers to each other, the coupler including an adjustment mechanism for matching axes of the optical fibers (Japanese Patent Laid-open Publication No. S59-135415).
Japanese Patent Laid-open Publication No. H10-300987 discloses that mutual position adjustment is necessary when fixating the optical fiber with respect to the LED, but does not clearly disclose a concrete mechanism for doing so. Meanwhile, Japanese Patent Laid-open Publication No. S52-102746 discloses a mechanism accurately matching the positions of center axes of the light-receiving surface of the optical fiber and the light-emitting surface of the LED, which are positioned facing each other in close proximity. However, the mechanism of Japanese Patent Laid-open Publication No. S52-102746 uses an elastic body for the adjustment mechanism and cannot be said to be sufficient from a standpoint of ensuring stability and accuracy of an adjusted state. In this regard, Japanese Patent Laid-open Publication No. 2005-345984 has a configuration in which the optical fiber and the LED are adjusted so as to be in a favorable positional relationship, after which the optical fiber and LED are fixated by a fixating member, thus ensuring stability of the adjusted state. However, the mechanism of Japanese Patent Laid-open Publication No. 2005-345984 has play in each component, as an adjustment margin, during adjustment and an adjustment operation to achieve a favorable positional relationship of the optical fiber and the LED is not necessarily easy. Moreover, fixation can be performed after adjustment in Japanese Patent Laid-open Publication No. S59-135415 as well, but, similar to Japanese Patent Laid-open Publication No. 2005-345984, the adjustment operation is not easy.
As in the above-noted Japanese Patent Laid-open Publication Nos. 2005-345984 and S59-135415, even when stability of the adjusted state is obtained by performing fixation after the adjustment operation, when there is play in the components during adjustment, highly accurate position adjustment becomes difficult. In particular, in the mechanisms of Japanese Patent Laid-open Publication Nos. S52-102746, 2005-345984, and S59-135415, the axis center position of the optical fiber can be matched for each axis direction along the light-receiving surface of the LED, but inclination or the like of the axis center of the optical fiber is difficult to adjust. For example, in the mechanism of Japanese Patent Laid-open Publication No. S59-135415, the inclination of the axis center direction of the optical fiber can be regulated by adjusting fixating screws in two locations mutually offset in the axis center direction of the optical fiber, but because there is nothing determining the position of the optical fiber during adjustment, highly accurate positioning adjustment is difficult.